MeowChan 1.0 🐾 — Your offline archive, upgraded

More chans. Better reading. A whole lot more control.

MeowChan 1.0 is here! This is a big update: a major desktop UI rework, 11 imageboard sources, five local media filters, and new ways to find, read, organize and clean up your collection. There is plenty to explore whether you want a compact downloader or a full offline reading workspace.

Before upgrading, back up your whole profile and media. See the upgrade and fallback notes below.

Download 1.0.0 →

The good stuff

• A fresh workspace that still feels like MeowChan. The Semi + Ursa UI rework brings clearer layouts, roomier controls, better spacing and more consistent dialogs across Downloads, Archive, Settings and Plugins. Keep it compact in Barebones, or bring more controls into view with Simple and Advanced. Settings now has eight focused categories, with drafts kept as you switch pages. Light and Dark, English and German are built in.
• Eleven sources. One collection. The 16 supplied plugins include eleven sources and five local filters. Alongside 4chan and 8kun, the source plugins cover Lainchan, Kohlchan, Wizchan, Endchan, 2ch, Leftypol, Uboachan, ZZZchan and SushiChan. The plugin overview puts descriptions and everyday actions first. Want to tinker? 14 editable C# examples and the bundled compiler let you get started without installing the .NET SDK. Experimental sources are clearly marked and start disabled; see the permission notes below.
• Keep the media you actually want. Choose from dimensions, file-size and original-name rules, a SHA-256 blocklist, animation/actual-format checks and PNG metadata-field detection. Filters work on locally staged files before they enter the archive. One filter applies per effective rule.
• Make time for the reading. Save named reader groups, navigate captured posts with the keyboard, and use optional Continue reading to pick up at your saved place through the topbar book button. Keep post bookmarks and notes, and make the app's shortcuts your own.
• Find it again. Combine source, board, state and date filters, then save searches you use often. Star threads and media, rate media, and return to the parts of your archive you care about.
• Less clutter, more collection. Clean up archive… previews threads with 0–2 saved media versions while protecting favorites, ratings, bookmarks, notes, reader groups, reading positions and entries still in use. Review the losses and choose what to delete. Archive counts now reflect stored media rather than an empty current download job.
• Give the media some room. The gallery follows your theme and offers an optional media focus view that folds away tools and details while keeping navigation close at hand. Video gets a compact Play/Pause, seek, audio and repeat strip. Repeat applies to the current medium; audio controls explain when a track or usable output is unavailable.

Try a reader group, save your favorite archive search, or finally clear out the threads you never meant to keep. Portable HTML exports remain a way to take your saved posts and verified originals with you.

Get MeowChan 1.0.0

All five primary packages include .NET and VLC; no .NET SDK installation is needed.

Platform	Download
Windows x64	ZIP
macOS — Apple Silicon	DMG
macOS — Intel	DMG
Linux x64	AppImage
Linux ARM64	AppImage

Linux bundled-VLC and system-VLC tar archives are also supplied. The system-VLC variant requires compatible system VLC. Make an AppImage executable before launching it. macOS apps are ad-hoc signed and not notarized; first launch may require approval in Privacy & Security. See the first-launch guidance.

candidate-inventory.json records the package source and validation run; SHA256SUMS covers the downloads. Developer NuGet packages and native dependency source archives accompany the desktop packages. The unchanged MeowChan-0.9.0-video-sources.tar.gz is the common upstream source base, not an old application build; use it together with the macOS source overlay. Separate source companions cover Linux.

Application filenames use 01- to 09- prefixes to keep the main downloads first. The unchanged CI inventory records their original filenames without those prefixes; SHA256SUMS uses the published filenames.

Reading, filters and archive counts: the details

Reader groups contain manually selected threads and do not change watches or downloads. **Continue reading** is optional: enable it in Settings to remember one explicitly read place per profile. Archive date filters use local registration dates. Rule templates copy selected values into an editable draft; saving remains explicit. Filters do not chain or automatically tag media. The **Saved versions** column counts archived media versions across a thread's recorded media folders, independently of the current download job and media filters. Missing files and files whose length differs from the manifest are not counted; unreadable storage appears as unavailable. This count checks presence and length; opening media still verifies its checksum. Cleanup previews threads with 0–2 verified saved media versions. Unknown storage is excluded. Review the current losses and explicitly confirm permanent local deletion. The first full inventory can take time on a large archive; back up before deleting. Plugin enable/disable applies to the selected valid build immediately; saved settings and candidate choices apply at the next start. See the [first-session guide](https://github.com/grassmann-it/MeowChan/blob/v1.0.0/docs/plugins/using-plugins.md#first-session) and [filter guide](https://github.com/grassmann-it/MeowChan/blob/v1.0.0/docs/plugins/local-media-filters.md).

Experimental sources and integrity permissions

**Kohlchan, Wizchan, Endchan, 2ch, Leftypol, Uboachan, ZZZchan and SushiChan are Experimental.** These sources start disabled when first registered in a profile. Existing profiles retain saved activation and permission choices. The Experimental label itself grants no exception. For **2ch, Uboachan, ZZZchan and SushiChan**, submitting a matching URL offers activation with strict integrity checks. These four sources have no provider-mismatch permission. Uboachan's supplied per-attachment SHA-1 values are verified. Approximate provider sizes remain separate raw hints rather than invented exact byte expectations. 2ch original redirects are checked against explicitly declared original-media hosts at every hop. For **Kohlchan, Wizchan, Endchan and Leftypol**, provider size or MD5 can differ from delivered bytes. **Activate and allow differences** (**Aktivieren und Abweichungen erlauben**) explicitly activates the source and permits provider size/MD5 differences for the current profile, plugin owner and source. Cancel grants nothing. Activation and permission are saved separately: existing watches may resume after activation, while submitted URLs wait for both steps to succeed. If permission saving fails, activation may already be saved; review the state and retry explicitly. Closing does not undo saved activation. Use **Sources** to review or revoke **Allow provider size and MD5 mismatches**. Manual **Enable plugin** grants no exception; a later URL for an active source does not restore a revoked permission. Retry previous failed media explicitly through **Downloads → thread details → Retry missing media**; granting permission does not automatically retry old failures. Provider metadata and measured local values stay separate. Supplied provider SHA-1/SHA-256, local verification, complete transfers, actual byte/pixel/storage limits, filters and cancellation remain enforced. Revoking permission blocks new acceptance that needs it; previously accepted archive media remains readable when its local length and SHA-256 verify. New attachment revisions need their own valid binding. See the [permission guide](https://github.com/grassmann-it/MeowChan/blob/v1.0.0/docs/plugins/using-plugins.md#experimental-sources-and-media-checks).

Upgrading — and what to do if something breaks

Please report bugs as GitHub issues. If 1.0 gives you trouble, 0.9.0 is still available. Use an untouched profile or a pre-upgrade backup when going back.

Close every older writer before upgrading. Back up the whole profile and media, and keep exports separately. Do not let 0.9.0 and 1.0 write to the same data simultaneously. Trying a separate profile (MEOWCHAN_PROFILE) and media directory first is useful.

1.0 writes archive schema 5 and media manifest 4. Older records remain readable in 1.0, including bindings without the new optional evidence. There is no supported downgrade of a profile changed by 1.0: to try 0.9.0 after a problem, use an untouched profile or restore your pre-upgrade backup to a separate location. Keep the 1.0 data available when reporting the issue.

For plugin and library authors

The Library, PluginSdk and optional PluginHost package version is `1.0.0`; the independent plugin SDK protocol contract remains `1.0.0`. Their public APIs are **not stable throughout 1.x**. Plugin authors should use the exact delivered SDK package and consult the [author guide](https://github.com/grassmann-it/MeowChan/blob/v1.0.0/docs/plugins/README.md). Local C# plugins run with user permissions; worker separation is not an OS sandbox. Custom library providers must explicitly bind new captured attachment revisions to the acquisition committed by the media store. Downloading without references and later capturing matching metadata no longer creates an implicit association. Update the provider logic and rebuild; recompilation alone does not migrate that behavior. See the [migration note](https://github.com/grassmann-it/MeowChan/blob/v1.0.0/CHANGELOG.md#breaking-librarysdk) and [package consumer example](https://github.com/grassmann-it/MeowChan/blob/v1.0.0/samples/LibMeowChan.Consumer/README.md).

Known limits

• Automated and hosted native checks apply to their recorded source and environment. Everyday testing is not comprehensive across every platform and device; physical audio/GPU/FUSE behavior and complete screen-reader/IME coverage remain limited.
• Source reachability and future provider behavior are not guaranteed. Live checks use bounded samples; they do not establish availability of every board, thread or attachment, or prove the causes of every historical metadata conflict.
• Plugin-supplied names and parameter labels can remain in English; the host interface follows its selected language.
• macOS packages are ad-hoc signed and not notarized.
• Automatic settings-backup recovery disables recovered experimental-source exceptions until you explicitly grant them again. Valid primary settings keep their saved choices.

Report a problem

Open an issue with the exact version/package, OS/CPU, display scaling, view mode, reproduction steps, expected and actual behavior. Mention whether the profile is fresh or upgraded and which plugins are enabled. Relevant logs and screenshots help. If you try 0.9.0 as a fallback, use a separate untouched profile or pre-upgrade backup and include whether the problem also occurs there.

Build provenance

Source: 9013ea1. GitHub Actions package and validation run. Automated runner checks are not physical hardware or everyday-use acceptance.